KR20060130316A - Driving circuit for display device and liquid crystal display device using the same - Google Patents

Abstract

A driving circuit for a display device and an LCD using the same are provided to minimize the length of a signal line, thereby suppressing the distortion of signal due to the increase in a resistance of the signal line. An LCD comprises a plurality of wires and a plurality of drivers. Each driver includes first and second input lines(71,72), an IC(100), and first and second output lines(61,62). The first and second input lines, respectively, transmit first and second input signals for generating first and second output signals. The IC receives the first or second input signal to generate the first or second output signal. The first and second output lines, respectively, transmit the first and second output signals. At least one of the plurality of drivers is operated such that the first input signal is transmitted to the second input line and the first output signal is transmitted to the second output line.

Description

Driving circuit for display device and liquid crystal display device using the same {Driving Circuit for Display Device and Liquid Crystal Display Device Using the Same}

1A and 1B are plan views of a liquid crystal display substrate according to the prior art;

2 is a plan view of a liquid crystal display substrate according to an embodiment of the present invention;

3 is a view for explaining the principle of operation of the present invention,

4 is a plan view of a liquid crystal display substrate according to another embodiment of the present invention;

5A and 5B illustrate the operation of the present invention.

♧ explanation of symbols for main parts of drawing

10-Board 20-Gate Line

30-data line 40, 50-drive circuit

61-1st output line 62-2nd output line

71-First Input Line 72-Second Input Line

90-pixel electrode 100-integrated circuit

T: thin film transistor

The present invention relates to a flat panel display, and more particularly, to a liquid crystal display using a liquid crystal.

Recently, as the demand for portable electronic products such as notebook computers and mobile phones increases, the demand for a flat panel display (FPD) that is not thick and light is increasing. In particular, liquid crystal displays (LCDs) among the flat panel display devices have recently been widely used because they are lighter in weight, smaller in volume, and operate with smaller power than other display devices having the same screen size.

The liquid crystal display transmits an image by converting an input electrical signal into visual information by using a property in which light transmittance of a liquid crystal, which is an intermediate state material between a liquid and a crystal, changes according to an applied voltage. That is, a conventional liquid crystal display device is composed of two substrates provided with electrodes and liquid crystals injected between the substrates, and an electric field is applied to the liquid crystals by applying different voltages to the electrodes on the two substrates. As the arrangement of molecules changes, the light transmittance changes.

Among the two substrates, a common electrode to which a reference voltage is commonly applied is formed on an upper substrate, whereas pixels are formed on a lower substrate and a pixel electrode to which a different data voltage is applied to each pixel. The lower substrate will be described in more detail with reference to the accompanying drawings.

1A and 1B are plan views of a liquid crystal display substrate according to the prior art.

Referring to FIG. 1A, wirings 2 and 3 are formed on a substrate 1 in a matrix form in a row direction and a column direction. Among the wirings 2 and 3, the column direction wiring 2 corresponds to the data line 3, and the row direction wiring 3 corresponds to the gate line 2. In this case, a region in which the gate line 2 and the data line 3 intersect each other in the row and column directions corresponds to a pixel region, and each pixel region includes a thin film transistor T and a pixel electrode 9. The gate line 2 is connected to the gate electrode of the thin film transistor T, and when the gate signal is transmitted to the gate line 2, the thin film transistor T is turned on. The data line 3 is connected to the source electrode of the thin film transistor T. When a source signal is transmitted to the data line 3, a voltage is applied to the pixel electrode 9 through the source / drain electrode of the thin film transistor T. .

The signals transmitted to the gate line 2 and the data line 3 are generated in the gate driving circuit 5 and the source driving circuit 4, respectively. The source driving circuit 4 and the gate driving circuit 5 are composed of a plurality of driving units 4a, 4b, and 5a. Each driving unit 4a, 4b, 5a has an integrated circuit therein and image information from the outside. It receives the light and generates the necessary signal. As shown in Fig. 1A, a single driver 4a, 4b, 5a generates a signal for a plurality of wirings 2,3. The signal generated at this time is transmitted to the gate line 2 and the data line 3 via the signal lines 6 and 8. However, there are the following problems with respect to the driving units 4a, 4b, and 5a.

1B is a diagram illustrating a problem of the prior art.

The substrate of FIG. 1B has the same resolution as that of FIG. 1A, but shows an increase in the size of the substrate 1. As the screen is increased while maintaining the same resolution as described above, various display devices have recently increased in size. Referring to FIG. 1B, it can be seen that as the size of the substrate 1 increases, the distance between the gate lines 2 and the distance between the data lines 3 increase (W <W '). As shown in FIG. 1B, even when the distance between the data lines 3 increases as the substrate 1 increases, the sizes of the source drivers 4a and 4b remain the same. The same applies to the gate driver 5a, but for convenience of explanation, only the matters related to the source drivers 4a and 4b are examined. This is because the integrated circuits included in the source drivers 4a and 4b are usually standardized in size, and are not easily changed in size due to the cost of materials. As a result, when the source drivers 4a and 4b have the same size but the interval between the data lines 3 connected to the source drivers 4a and 4b increases, a signal connecting the source drivers 4a and 4b to the data lines 3 is increased. The length of the line 6 is increased.

As the length of the signal line 6 increases as described above, the resistance value of the signal line 6 increases in proportion to the length of the corresponding signal line 6. As the resistance increases, the signal value transmitted along the corresponding wirings 2 and 3 decreases. Specifically, among the data lines 3 connected to the source drivers 4a and 4b, the resistance increase in the data line 3 farthest from the source drivers 4a and 4b is remarkable, so that different source drivers 4a and 4b are different. ), The screen may appear dark in an area (hatched portion of FIG. 1B) connected to the boundary of the data line 3.

The same problem as above occurs for the gate line 2 and the gate driver 5a.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a driving circuit for a display device capable of maintaining a resistance value of a signal line connecting a driver and a wiring even when the wiring interval increases, and a liquid crystal display using the same. To provide a device.

In order to achieve the above technical problem, the present invention provides a driving circuit for a display device. The driving circuit for the display device of the present invention; A plurality of driving parts connected to a plurality of wirings arranged in one direction on a substrate and generating and transmitting an output signal including a first output signal and a second output signal to the wirings; The driving unit may include a first input line for transmitting a first input signal for generating the first output signal and a second input line for transmitting a second input signal for generating the second output signal, the first input signal, or An integrated circuit receiving a second input signal and generating a first output signal or a second output signal, respectively, a first output line transmitting the first output signal generated in the integrated circuit and the second output signal; Including a second output line; At least one driving unit of the plurality of driving units may be configured to transmit the first input signal to the second input line and to transmit the first output signal to the second output line.

The driving circuit for the display device as described above can be used in the liquid crystal display device. Specifically, the liquid crystal display device of the present invention includes a substrate and a plurality of first wirings and drive circuits arranged in one direction on the substrate, and the drive circuit for display devices of the present invention described above is used as the drive circuit.

A plurality of second wires intersecting the first wires are formed on the substrate, and in a region where the first wires and the second wires cross, a gate electrode extending from the second wires and the first wires extend. A thin film transistor is formed that includes a source electrode and a drain electrode formed to face the source electrode. Here, if the driving unit is a source driving unit for the source electrode, a signal for a source electrode is generally transmitted to the first input / output line, and the second input / output line may be used for signal transmission for additional purposes. In practice, however, since the second input / output line is used only for a limited use in a few driving units, the second input / output line may also be used for transmitting a source signal except for a specific use. Used.

The advantage of using the second input / output line for the same purpose as the first input / output line is that it is possible to prevent an increase in resistance of the signal line connected to the input / output line and transmitting a source signal. to be. The second input / output line is connected to the edge of the integrated circuit, and the signal line connected to the second output line is bonded at the edge of the driver. At this time, the length of the signal line connecting the driver and the first wiring varies depending on the position at which the driver is joined. When the signal line is connected to the second output line, the signal line is joined to the edge of the driver and may be shortened. have. However, since the resistance of the wire is inversely proportional to the length, the shorter the signal line, the smaller the resistance value.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be applied and modified in various forms. Rather, the following embodiments are provided so that the technical spirit disclosed by the present invention more clearly and further, the technical spirit of the present invention may be sufficiently delivered to those skilled in the art having an average knowledge in the field to which the present invention belongs. Therefore, the scope of the present invention should not be construed as limited by the embodiments described below. In addition, in the drawings presented in conjunction with the following examples, the size of layers and regions are simplified or somewhat exaggerated to emphasize clarity, and like reference numerals in the drawings indicate like elements.

2 is a plan view of a liquid crystal display substrate according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the wirings 20 and 30 are formed on the substrate 10 in a matrix form in a row direction and a column direction. In this case, the column direction wiring represents the data line 30 and the row direction wiring 30 represents the gate line 20. In this case, a region in which the gate line 20 and the data line 30 cross each other in the row and column directions corresponds to a pixel region, and each pixel region includes a thin film transistor T and a pixel electrode 90. The thin film transistor T includes a gate electrode / source electrode / drain electrode. The gate electrode / source electrode is formed by extending the gate line / source line. In addition, the drain electrode is formed to face the source electrode, and one end thereof is in contact with the pixel electrode 90. At this time, a gate signal and a source signal are transmitted along the gate line 20 and the data line 30, and when the thin film transistor T is turned on according to the gate signal, a data voltage is applied to the pixel electrode 90 according to the source signal. Is approved.

Signals transmitted to the data line 30 and the gate line 20 are generated in the source driving circuit 40 and the gate driving circuit 50, respectively. The driving circuits 40 and 50 are composed of a plurality of driving units 40a, 40b and 50a. Each of the driving units 40a, 40b and 50a is provided with an integrated circuit therein and receives input signals related to image information from the outside. It receives the signal and generates the required output signal. As shown in FIG. 2, a single driver 40a, 40b, 50a controls the plurality of wires 20, 30. In FIG. 2, for convenience, a single driver 40a, 40b, 50a uses four wires ( An example of generating a signal for 20,30 is shown. Output signals generated by the drivers 40a, 40b, and 50a are transmitted to the data line 30 or the gate line 20 through the signal lines 65 and 80.

Looking at the source drivers 40a and 40b and the signal lines 65 connected thereto, the length of the signal lines 65 is reduced compared to the prior art. In particular, the lengths of the first signal line 66 and the fourth signal line 69 are reduced compared to the signal line 6 in the conventional liquid crystal display shown in FIG. 1B. When the length of the signal line 65 is reduced in this manner, the resistance value proportional to the length of the signal line 65 is also reduced. As a result, the source signal value transmitted along the signal line 65 may also be transmitted to the data line 30 without being reduced in the transmission process. Therefore, as shown in the related art, it is possible to prevent the screen from darkening due to the decrease of the source signal value due to the increase in the resistance of the signal line 65.

The length of the signal line 65 is reduced in the present invention because the position at which the signal line 65 is bonded on the source drivers 40a and 40b is changed. Comparing FIG. 1B with FIG. 2, the conventional signal line 6 is joined to the center of the source driver 4a and 4b, whereas the signal line 65 of the present invention is the center of the source driver 40a and 40b. And edges. The signal lines 66 and 69 bonded to the edges of the source drivers 40a and 40b may be reduced in length by the separation distance between the center and the edges of the drivers 40a and 40b. The reason why the junction position of the signal line 65 can be changed is as follows.

3 is a view for explaining the principle of operation of the present invention, showing the inside of the source driving unit.

Referring to FIG. 3, the source driver 40a has an integrated circuit 100 embedded therein, and the input circuits 71 and 72 and the output lines 61 and 62 are connected to the integrated circuit 100. The input lines 71 and 72 and the output lines 61 and 62 are divided into two types. That is, there is a first input line 71 and a first output line 61 connected to the center of the integrated circuit 100, and a second input line 72 and a second input line connected to the edge portion of the integrated circuit 100. There are two output lines 62. The first input signal is input to the first input line 71 and the first output signal is output to the first output line 61. In addition, a second input signal is input to the second input line 72 and a second output signal is output to the second output line 62. The first input / output signal represents a signal for image information and a data voltage for realizing the same in the source driver 40a. The second input / output signal includes information for performing an additional function separately from the image information. As shown in a dotted line in FIG. 3, the second input line 72 and the second output line 62 are integrated circuits 100. It may also be formed as a bypass line without passing through).

However, the second input line 72 and the second output line 62 are used only for a limited purpose and are not often used in practice. In view of this, in the present invention, not only the first input line 71 and the first output line 61 but also the second input line 72 and the second output line 62 transmit the first input / output signal. It is used to To this end, as shown in FIG. 3, the second input line 72 and the second output line 62 are formed to pass through the integrated circuit 100, not the bypass line. In this case, the first input line 71 and the first output line 61 are formed at the center of the integrated circuit 100, and the second input line 72 and the second output line 62 are integrated circuit 100. It is formed to pass through the edge of). Similarly, the first output line 61 is joined to an external signal line 65 in the central region of the driver 40a, and the second output line 62 is externally located near the corner farthest from the central portion of the driver 40a. It is bonded with the signal line 65 of. Thus, as shown in FIG. 2, the first signal line 66 and the fourth signal line 69 connected to the source driver 40a may be joined at the edge of the driver 40a. In this case, the length of the signal lines 66 and 68 may be reduced to suppress the increase in resistance.

In the embodiment shown in FIG. 2, both the second input line and the second output line of the source driver are used to transmit the first input signal and the first output signal. However, the second input line and the second output line may be used to transmit the second input signal and the second output signal for a specific purpose. Hereinafter, a specific embodiment corresponding to the above case will be described.

4 is a plan view of a liquid crystal display substrate according to another exemplary embodiment of the present invention.

In the drawings, the data line 30, the gate line 20, the thin film transistor T, and the pixel electrode 90 have been described above, and detailed description thereof will be omitted. In FIG. 4, the source driving circuit 40 is connected to a separate printed circuit board 101, and typically, a separate printed circuit board is also provided for the gate driving circuit 50. However, since the weight and volume increase as the screen size of the liquid crystal display increases, various technologies have been developed to reduce the area and volume occupied by portions other than the screen while constructing a large screen. 4 is one of such various techniques in which a printed circuit board for the gate drive circuit 50 is removed and the gate drive circuit 50 is located directly in the substrate 10. At this time, the external signal for generating the gate signal is transmitted to any one of the gate driver 50a via any one source driver 40a 'constituting the source driver circuit 40. In addition, the plurality of gate drivers 50a and 50b are connected to each other by a signal line 65 '.

In FIG. 4, the number of signal lines 65, 65 ′ connected to the first source driver 40a ′ and the second source driver 40b is different from the left side, and the former is connected to the data line 30. In addition, a signal line 60 ′ that transmits a signal to the gate driver 50a is added.

5A and 5B illustrate an operation process of the present invention and correspond to the internal operation process of the first source driver 40a ′ and the second source driver 40b of FIG. 4, respectively.

Referring to FIG. 5A, the driver 40a ′ includes an integrated circuit 100, and the integrated circuit 100 includes first and second input lines 71 and 72 and first and second output lines. (61, 62) are connected. At this time, the first input signal is transmitted to the first input line 71 and the first output signal is transmitted to the first output line 71 (indicated by a solid arrow in the drawing). Here, the first input signal represents image information and the first output signal represents a signal for a data voltage for implementing the image information. On the other hand, the second input signal is transmitted to the second input line 72 and the second output signal is transmitted to the second output line 62 (indicated by a dotted arrow in the drawing), which is the signal line 60 '. It is transmitted to the gate driver 50a through the gate signal.

Referring to FIG. 5B, the integrated circuit 100 in the driver 40a includes four first input lines 71 and four first output lines 61, and a second input line 72 and a second output line 62. ) Are connected. At this time, the first input signal and the first output signal are also transmitted to the second input line 72 and the second output line 62 (indicated by the solid arrows in the drawing), respectively. Two of the output lines 61 are not used, and the first input signal and the first output signal are transmitted to the remaining two lines (indicated by solid arrows in the drawing). This is for the case where the second input line 72 and the second output line 62 are not used for a specific purpose, so that the external signal line 65 can be connected to the edge of the driving unit 40a if possible. .

Referring again to FIG. 4, in the above embodiment, only the first source driver 40a ′ uses the second input / output line for a specific purpose, and the second input / output line is used for the specific purpose in the remaining source driver 40b. This was used to transmit the first input / output signal in a state where there is no need. Accordingly, except for the signal line 65 connecting the first driver 40a 'and the data line 30, the signal line 65 may be shorter from the second driver 40b.

The liquid crystal display of the present invention has been described with reference to the exemplary drawings. In the exemplary drawing, the example in which the gate signal is transmitted as the case where the second input / output line is used for a specific purpose has been described. In addition, the second input / output line may be used for various purposes. For example, a conventional liquid crystal display device has a separate substrate on the upper side in addition to the substrate on which the data line / gate line is provided, and the same upper substrate is applied with the same reference voltage as a whole. The second input / output line of the particular driver may be used. In addition, in the embodiment of FIG. 4, only one of the plurality of driving units uses the second input / output line for a special purpose as shown in FIG. 5A, and the remaining driving unit uses the second input / output line as the first input as shown in FIG. 5B. It was used to transmit the input signal and the first output signal. However, the present invention may use as many driving units as necessary in the manner shown in FIG. 5A and use the remainder in the manner shown in FIG. 5B as necessary, and the number of driving units according to the method used is not limited. In addition, the position of the driving unit used in the manner shown in FIG. 5A is not particularly limited, and as shown in FIG. 4, for example, the position of the driving unit is not necessarily arranged first in the row direction.

As described above, according to the present invention, the length of a signal line for transmitting a signal required for operation can be minimized, and the resistance of the signal line is increased due to an increase in the length of the signal line in a large screen, and the signal is distorted. It can solve the problem.

Claims (11)

A plurality of driving parts connected to a plurality of wirings arranged in one direction on a substrate and generating and transmitting an output signal including a first output signal and a second output signal to the wirings; The driving unit, A first input line for transmitting a first input signal for generating the first output signal and a second input line for transmitting a second input signal for generating the second output signal; An integrated circuit receiving the first input signal or the second input signal and generating a first output signal or a second output signal, respectively; A first output line for transmitting the first output signal and a second output line for transmitting the second output signal generated in the integrated circuit; At least one driving unit of the plurality of driving units, And the first input signal is transmitted to the second input line, and the first output signal is transmitted to the second output line. The method of claim 1, And the second output line is connected to an edge of the integrated circuit. The method according to claim 1 or 2, And the first output signal is a source signal transmitted to a source electrode of a thin film transistor provided on the substrate through the wiring. The method of claim 3, wherein And the second output signal is a gate signal for driving the gate electrode of the thin film transistor. The method of claim 3, wherein And the second output signal is a signal for a voltage applied to another substrate provided to face the substrate. Board; A plurality of first wirings arranged in one direction on the substrate; A driving circuit connected to the first wiring, the driving circuit including a plurality of driving units to generate an output signal including a first output signal and a second output signal and to transmit the output signal to the first wiring; The driving unit, A first input line for transmitting a first input signal for generating the first output signal and a second input line for transmitting a second input signal for generating the second output signal; An integrated circuit receiving the first input signal or the second input signal and generating a first output signal or a second output signal, respectively; A first output line for transmitting the first output signal and a second output line for transmitting the second output signal generated in the integrated circuit; At least one driving unit of the plurality of driving units, And the first input signal is transmitted to the second input line, and the first output signal is transmitted to the second output line. The method of claim 6, And the second output line is connected to an edge of the integrated circuit. The method according to claim 6 or 7, A plurality of second wires are formed on the substrate to intersect the first wires. In the region where the first wiring and the second wiring intersect, a thin film transistor including a gate electrode extending from the second wiring, a source electrode extending from the first wiring, and a drain electrode formed to face the source electrode. Liquid crystal display characterized in that formed. The method of claim 8, And the first output signal is a source signal transmitted to the source electrode through the first wiring. The method of claim 9, And the second output signal is a gate signal for driving the gate electrode. The method of claim 9, And the second output signal is a signal corresponding to a voltage applied on another substrate facing the substrate.

Images